Azaborine compounds as host materials and dopants for PHOLEDs

ABSTRACT

Novel organic compounds comprising azaborine are provided. In particular, the compounds comprise a dibenzo-1,4,-azaborine core having a phenyl substituent on the boron atom, and aryl or heteroaryl substituents at positions 2 and 6 of the phenyl substituent. These compounds may be advantageously used in organic light-emitting devices to provide improved efficiency and lifetime.

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/780,599, filed May 14, 2010, the entire disclosure of whichis incorporated by reference herein.

The claimed invention was made by, on behalf of, and/or in connectionwith one or more of the following parties to a joint universitycorporation research agreement: Regents of the University of Michigan,Princeton University, The University of Southern California, and theUniversal Display Corporation. The agreement was in effect on and beforethe date the claimed invention was made, and the claimed invention wasmade as a result of activities undertaken within the scope of theagreement.

FIELD OF THE INVENTION

The present invention relates to novel organic compounds that may beadvantageously used in organic light-emitting devices (OLEDs). Moreparticularly, the invention relates to dibenzo-1,4-azaborine compoundscontaining aryl or heteroaryl substituents and their use in PHOLEDs.

BACKGROUND

Opto-electronic devices that make use of organic materials are becomingincreasingly desirable for a number of reasons. Many of the materialsused to make such devices are relatively inexpensive, so organicopto-electronic devices have the potential for cost advantages overinorganic devices. In addition, the inherent properties of organicmaterials, such as their flexibility, may make them well suited forparticular applications such as fabrication on a flexible substrate.Examples of organic opto-electronic devices include organiclight-emitting devices (OLEDs), organic phototransistors, organicphotovoltaic cells, and organic photodetectors. For OLEDs, the organicmaterials may have performance advantages over conventional materials.For example, the wavelength at which an organic emissive layer emitslight may generally be readily tuned with appropriate dopants.

OLEDs make use of thin organic films that emit light when voltage isapplied across the device. OLEDs are becoming an increasinglyinteresting technology for use in applications such as flat paneldisplays, illumination, and backlighting. Several OLED materials andconfigurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and5,707,745, which are incorporated herein by reference in their entirety.

One application for phosphorescent emissive molecules is a full colordisplay. Industry standards for such a display call for pixels adaptedto emit particular colors, referred to as “saturated” colors. Inparticular, these standards call for saturated red, green, and bluepixels. Color may be measured using CIE coordinates, which are wellknown to the art.

One example of a green emissive molecule is tris(2-phenylpyridine)iridium, denoted Ir(ppy)₃, which has the structure:

In this, and later figures herein, we depict the dative bond fromnitrogen to metal (here, Ir) as a straight line.

As used herein, the term “organic” includes polymeric materials as wellas small molecule organic materials that may be used to fabricateorganic opto-electronic devices. “Small molecule” refers to any organicmaterial that is not a polymer, and “small molecules” may actually bequite large. Small molecules may include repeat units in somecircumstances. For example, using a long chain alkyl group as asubstituent does not remove a molecule from the “small molecule” class.Small molecules may also be incorporated into polymers, for example as apendent group on a polymer backbone or as a part of the backbone. Smallmolecules may also serve as the core moiety of a dendrimer, whichconsists of a series of chemical shells built on the core moiety. Thecore moiety of a dendrimer may be a fluorescent or phosphorescent smallmolecule emitter. A dendrimer may be a “small molecule,” and it isbelieved that all dendrimers currently used in the field of OLEDs aresmall molecules.

As used herein, “top” means furthest away from the substrate, while“bottom” means closest to the substrate. Where a first layer isdescribed as “disposed over” a second layer, the first layer is disposedfurther away from substrate. There may be other layers between the firstand second layer, unless it is specified that the first layer is “incontact with” the second layer. For example, a cathode may be describedas “disposed over” an anode, even though there are various organiclayers in between.

As used herein, “solution processible” means capable of being dissolved,dispersed, or transported in and/or deposited from a liquid medium,either in solution or suspension form.

A ligand may be referred to as “photoactive” when it is believed thatthe ligand directly contributes to the photoactive properties of anemissive material. A ligand may be referred to as “ancillary” when it isbelieved that the ligand does not contribute to the photoactiveproperties of an emissive material, although an ancillary ligand mayalter the properties of a photoactive ligand.

As used herein, and as would be generally understood by one skilled inthe art, a first “Highest Occupied Molecular Orbital” (HOMO) or “LowestUnoccupied Molecular Orbital” (LUMO) energy level is “greater than” or“higher than” a second HOMO or LUMO energy level if the first energylevel is closer to the vacuum energy level. Since ionization potentials(IP) are measured as a negative energy relative to a vacuum level, ahigher HOMO energy level corresponds to an IP having a smaller absolutevalue (an IP that is less negative). Similarly, a higher LUMO energylevel corresponds to an electron affinity (EA) having a smaller absolutevalue (an EA that is less negative). On a conventional energy leveldiagram, with the vacuum level at the top, the LUMO energy level of amaterial is higher than the HOMO energy level of the same material. A“higher” HOMO or LUMO energy level appears closer to the top of such adiagram than a “lower” HOMO or LUMO energy level.

As used herein, and as would be generally understood by one skilled inthe art, a first work function is “greater than” or “higher than” asecond work function if the first work function has a higher absolutevalue. Because work functions are generally measured as negative numbersrelative to vacuum level, this means that a “higher” work function ismore negative. On a conventional energy level diagram, with the vacuumlevel at the top, a “higher” work function is illustrated as furtheraway from the vacuum level in the downward direction. Thus, thedefinitions of HOMO and LUMO energy levels follow a different conventionthan work functions.

More details on OLEDs, and the definitions described above, can be foundin U.S. Pat. No. 7,279,704, which is incorporated herein by reference inits entirety.

SUMMARY OF THE INVENTION

Azaborine compounds are provided, the compounds comprising the formula:

R₁ is a group containing two or more aryl or heteroaryl groups, and thearyl or heteroaryl groups are conjugated or fused. R₃ and R₄ mayrepresent mono, di, tri, tetra, or penta substitutions. R₂, R₃ and R₄are independently selected from hydrogen, alkyl, alkoxy, amino, alkenyl,alkynyl, aryl, and heteroaryl. Preferably, R₂ includes an aryl or aheteroaryl.

In one aspect, the compound comprises the formula:

R′₃, R′₅, and R₆ may represent mono, di, tri, tetra, or pentasubstitutions. R′₁, R′₂, R′₃, R′₄, R′₅ and R′₆ are independentlyselected from hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, aryl,and heteroaryl. At least one of R′₁ and R₂ is an aryl or heteroaryl andthe aryl or heteroaryl groups are conjugated or fused.

In one aspect, R′₃, R′₄, R′₅, and R′₆ are independently aryl orheteroaryl.

In another aspect, R′₄ includes aryl or heteroaryl substitutionspositioned ortho to the carbon atom in the aryl or heteroaryl group thatis connected to the nitrogen atom.

Specific examples of azaborine compounds are provided. In one aspect,the compounds are selected from the group consisting of:

In another aspect, the compounds are selected from the group consistingof:

Additionally, a first device comprising an organic light-emitting deviceis provided. The organic light-emitting device comprises an anode, acathode, and an organic layer, disposed between the anode and thecathode, and the organic layer further comprises a compound comprisingFormula I, as described above.

R₁ is a group containing two or more aryl or heteroaryl groups, and thearyl or heteroaryl groups are conjugated or fused. R₃ and R₄ mayrepresent mono, di, tri, tetra, or penta substitutions. R₂, R₃ and R₄are independently selected from hydrogen, alkyl, alkoxy, amino, alkenyl,alkynyl, aryl, and heteroaryl. Preferably, R₂ includes an aryl or aheteroaryl.

In one aspect, the compound comprises Formula II.

R′₃, R′₄, R′₅, and R₆ may represent mono, di, tri, tetra, or pentasubstitutions. R′₁, R′₂, R′₃, R′₄, R′₅ and R′₆ are independentlyselected from hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, aryl,and heteroaryl. At least one of R′₁ and R₂ is an aryl or heteroaryl, andthe aryl or heteroaryl groups are conjugated or fused.

In one aspect, R′₃, R′₄, R′₅, and R′₆ are independently aryl orheteroaryl.

In another aspect, R′₄ includes aryl or heteroaryl substitutionspositioned ortho to the carbon atom in the aryl or heteroaryl group thatis connected to the nitrogen atom.

Specific examples of azaborine compounds that may be used in the devicesare provided, and include compound selected from the group consisting ofCompounds 1-48. In another aspect, azaborine compounds that may be usedin the devices are provided, and include compound selected from thegroup consisting of Compounds 49-60.

In one aspect, the organic layer is a blocking layer and the compoundhaving Formula is a blocking material.

In another aspect, the organic layer is an emissive layer and thecompound comprising Formula I is a host. The organic layer may furthercomprise an emissive dopant. In yet another aspect, the organic layer isan emissive layer and the compound comprising Formula I is a fluorescentemitter.

In one aspect, the first device is a consumer product. In anotheraspect, the first device is an organic light-emitting device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an organic light-emitting device.

FIG. 2 shows an inverted organic light-emitting device that does nothave a separate electron transport layer.

FIG. 3 shows an azaborine compound.

FIG. 4 shows the photoluminescence spectra of Compound 2.

FIG. 5 shows the photoluminescence spectra of Compound X.

FIG. 6 shows the photoluminescence spectra of Compound Y.

DETAILED DESCRIPTION

Generally, an OLED comprises at least one organic layer disposed betweenand electrically connected to an anode and a cathode. When a current isapplied, the anode injects holes and the cathode injects electrons intothe organic layer(s). The injected holes and electrons each migratetoward the oppositely charged electrode. When an electron and holelocalize on the same molecule, an “exciton,” which is a localizedelectron-hole pair having an excited energy state, is formed. Light isemitted when the exciton relaxes via a photoemissive mechanism. In somecases, the exciton may be localized on an excimer or an exciplex.Non-radiative mechanisms, such as thermal relaxation, may also occur,but are generally considered undesirable.

The initial OLEDs used emissive molecules that emitted light from theirsinglet states (“fluorescence”) as disclosed, for example, in U.S. Pat.No. 4,769,292, which is incorporated by reference in its entirety.Fluorescent emission generally occurs in a time frame of less than 10nanoseconds.

More recently, OLEDs having emissive materials that emit light fromtriplet states (“phosphorescence”) have been demonstrated. Baldo et al.,“Highly Efficient Phosphorescent Emission from OrganicElectroluminescent Devices,” Nature, vol. 395, pp. 151-154, 1998;(“Baldo-I”) and Baldo et al., “Very high-efficiency green organiclight-emitting devices based on electrophosphorescence,” Appl. Phys.Lett., vol. 75, No. 3, pp. 4-6, 1999 (“Baldo-II”), which areincorporated by reference in their entireties. Phosphorescence isdescribed in more detail in U.S. Pat. No. 7,279,704 at cols. 5-6, whichare incorporated by reference.

FIG. 1 shows an organic light-emitting device 100. The figures are notnecessarily drawn to scale. Device 100 may include a substrate 110, ananode 115, a hole injection layer 120, a hole transport layer 125, anelectron blocking layer 130, an emissive layer 135, a hole blockinglayer 140, an electron transport layer 145, an electron injection layer150, a protective layer 155, and a cathode 160. Cathode 160 is acompound cathode having a first conductive layer 162 and a secondconductive layer 164. Device 100 may be fabricated by depositing thelayers described, in order. The properties and functions of thesevarious layers, as well as example materials, are described in moredetail in U.S. Pat. No. 7,279,704 at cols. 6-10, which are incorporatedby reference.

More examples for each of these layers are available. For example, aflexible and transparent substrate-anode combination is disclosed inU.S. Pat. No. 5,844,363, which is incorporated by reference in itsentirety. An example of a p-doped hole transport layer is m-MTDATA dopedwith F.sub.4-TCNQ at a molar ratio of 50:1, as disclosed in U.S. PatentApplication Publication No. 2003/0230980, which is incorporated byreference in its entirety. Examples of emissive and host materials aredisclosed in U.S. Pat. No. 6,303,238 to Thompson et al., which isincorporated by reference in its entirety. An example of an n-dopedelectron transport layer is BPhen doped with Li at a molar ratio of 1:1,as disclosed in U.S. Patent Application Publication No. 2003/0230980,which is incorporated by reference in its entirety. U.S. Pat. Nos.5,703,436 and 5,707,745, which are incorporated by reference in theirentireties, disclose examples of cathodes including compound cathodeshaving a thin layer of metal such as Mg:Ag with an overlyingtransparent, electrically-conductive, sputter-deposited ITO layer. Thetheory and use of blocking layers is described in more detail in U.S.Pat. No. 6,097,147 and U.S. Patent Application Publication No.2003/0230980, which are incorporated by reference in their entireties.Examples of injection layers are provided in U.S. Patent ApplicationPublication No. 2004/0174116, which is incorporated by reference in itsentirety. A description of protective layers may be found in U.S. PatentApplication Publication No. 2004/0174116, which is incorporated byreference in its entirety.

FIG. 2 shows an inverted OLED 200. The device includes a substrate 210,a cathode 215, an emissive layer 220, a hole transport layer 225, and ananode 230. Device 200 may be fabricated by depositing the layersdescribed, in order. Because the most common OLED configuration has acathode disposed over the anode, and device 200 has cathode 215 disposedunder anode 230, device 200 may be referred to as an “inverted” OLED.Materials similar to those described with respect to device 100 may beused in the corresponding layers of device 200. FIG. 2 provides oneexample of how some layers may be omitted from the structure of device100.

The simple layered structure illustrated in FIGS. 1 and 2 is provided byway of non-limiting example, and it is understood that embodiments ofthe invention may be used in connection with a wide variety of otherstructures. The specific materials and structures described areexemplary in nature, and other materials and structures may be used.Functional OLEDs may be achieved by combining the various layersdescribed in different ways, or layers may be omitted entirely, based ondesign, performance, and cost factors. Other layers not specificallydescribed may also be included. Materials other than those specificallydescribed may be used. Although many of the examples provided hereindescribe various layers as comprising a single material, it isunderstood that combinations of materials, such as a mixture of host anddopant, or more generally a mixture, may be used. Also, the layers mayhave various sublayers. The names given to the various layers herein arenot intended to be strictly limiting. For example, in device 200, holetransport layer 225 transports holes and injects holes into emissivelayer 220, and may be described as a hole transport layer or a holeinjection layer. In one embodiment, an OLED may be described as havingan “organic layer” disposed between a cathode and an anode. This organiclayer may comprise a single layer, or may further comprise multiplelayers of different organic materials as described, for example, withrespect to FIGS. 1 and 2.

Structures and materials not specifically described may also be used,such as OLEDs comprised of polymeric materials (PLEDs) such as disclosedin U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated byreference in its entirety. By way of further example, OLEDs having asingle organic layer may be used. OLEDs may be stacked, for example asdescribed in U.S. Pat. No. 5,707,745 to Forrest et al, which isincorporated by reference in its entirety. The OLED structure maydeviate from the simple layered structure illustrated in FIGS. 1 and 2.For example, the substrate may include an angled reflective surface toimprove out-coupling, such as a mesa structure as described in U.S. Pat.No. 6,091,195 to Forrest et al., and/or a pit structure as described inU.S. Pat. No. 5,834,893 to Bulovic et al., which are incorporated byreference in their entireties.

Unless otherwise specified, any of the layers of the various embodimentsmay be deposited by any suitable method. For the organic layers,preferred methods include thermal evaporation, ink-jet, such asdescribed in U.S. Pat. Nos. 6,013,982 and 6,087,196, which areincorporated by reference in their entireties, organic vapor phasedeposition (OVPD), such as described in U.S. Pat. No. 6,337,102 toForrest et al., which is incorporated by reference in its entirety, anddeposition by organic vapor jet printing (OVJP), such as described inU.S. patent application Ser. No. 10/233,470, which is incorporated byreference in its entirety. Other suitable deposition methods includespin coating and other solution based processes. Solution basedprocesses are preferably carried out in nitrogen or an inert atmosphere.For the other layers, preferred methods include thermal evaporation.Preferred patterning methods include deposition through a mask, coldwelding such as described in U.S. Pat. Nos. 6,294,398 and 6,468,819,which are incorporated by reference in their entireties, and patterningassociated with some of the deposition methods such as ink jet and OVJD.Other methods may also be used. The materials to be deposited may bemodified to make them compatible with a particular deposition method.For example, substituents such as alkyl and aryl groups, branched orunbranched, and preferably containing at least 3 carbons, may be used insmall molecules to enhance their ability to undergo solution processing.Substituents having 20 carbons or more may be used, and 3-20 carbons isa preferred range. Materials with asymmetric structures may have bettersolution processibility than those having symmetric structures, becauseasymmetric materials may have a lower tendency to recrystallize.Dendrimer substituents may be used to enhance the ability of smallmolecules to undergo solution processing.

Devices fabricated in accordance with embodiments of the invention maybe incorporated into a wide variety of consumer products, including flatpanel displays, computer monitors, televisions, billboards, lights forinterior or exterior illumination and/or signaling, heads up displays,fully transparent displays, flexible displays, laser printers,telephones, cell phones, personal digital assistants (PDAs), laptopcomputers, digital cameras, camcorders, viewfinders, micro-displays,vehicles, a large area wall, theater or stadium screen, or a sign.Various control mechanisms may be used to control devices fabricated inaccordance with the present invention, including passive matrix andactive matrix. Many of the devices are intended for use in a temperaturerange comfortable to humans, such as 18 degrees C. to 30 degrees C., andmore preferably at room temperature (20-25 degrees C.).

The materials and structures described herein may have applications indevices other than OLEDs. For example, other optoelectronic devices suchas organic solar cells and organic photodetectors may employ thematerials and structures. More generally, organic devices, such asorganic transistors, may employ the materials and structures.

The terms halo, halogen, alkyl, cycloalkyl, alkenyl, alkynyl,heterocyclic group, aryl, aromatic group, and heteroaryl are known tothe art, and are defined in U.S. Pat. No. 7,279,704 at cols. 31-32,which are incorporated herein by reference.

Novel azaborine compounds are provided that may be used as hostmaterials or fluorescent emissive dopant material in organiclight-emitting devices (illustrated in FIG. 3). 1,4-azaborine compoundsare particularly interesting heteroaromatic molecules because of theboron and nitrogen heteroatoms in the core of the compound. These1,4-azaborine compounds can display high singlet and triplet energiesdue to the lack of conjugation relative to their all-carbon congeners,and they are bright blue fluorescent emitters.

Anthracene derivatives and organic devices containing these compoundshave been reported in the literature, but the known compounds haveseveral problems that may limit their use in OLEDs. Anthracene is ahighly conjugated polyaromatic hydrocarbon. OLEDs with anthracenederivatives as the host materials, such as9,10-di-(2-naphthyl)anthracene, can have long device lifetimes. (See,Appl. Phys. Lett., Vol. 80, p. 3201 2002). However, the triplet energyof anthracene is very low (680 nm), due to the high conjugation, makingit unsuitable as a host material for OLEDs with phosphorescent emittersin the visible region. Dibenzo-1,4-azaborine is isolelectronic toanthracene. The center azaborine ring is semi-aromatic, so the degree ofconjugation may be reduced and the triplet energy may be higher comparedto anthracene. Therefore, azaborine compounds may be advantageously usedto raise the triplet energy of the host.

1,4-azaborine compounds have been reported in the literature (see, US2003/0157366). However, these trivalent boron compounds can bechemically unstable because the electron deficiency of the boron atommakes it susceptible to nucleophilic attack. Without being bound bytheory, it is believed that the boron atom may still need to beprotected to minimize chemical instability despite the semi-aromaticcharacter of the center ring in dibenzo-1,4-azaborine. HOMO, LUMO andlowest triplet energy (T₁), as calculated by DFT(Gaussian/B31yp/cep-31g), of some dibenzo-1,4-azaborine compounds areshown in Table 1.

TABLE 1 HOMO LUMO Dipole Structure (eV) (eV) Gap (eV) (D) T₁ (nm)

Compound 1 −5.29 −1.31 −3.98 3.52 449

Compound 2 −5.3 −1.34 −3.96 3.73 450

Compound 3 −5.32 −1.32 −3.99 2.88 447

Compound 4 −5.32 −1.34 -3.98 3.43 448

Compound 50 −5.00 −1.63 −3.37 5.95 596

Compound 51 −5.10 −1.32 −3.79 5.12 462

Compound 52 −5.28 −1.30 −3.97 4.87 462

Compound X −5.44 −1.38 −4.06 3.02 443

Compound Y −5.35 −1.33 4.02 3.43 447

Compound Z −5.09 −1.6 −3.48 0 717

Additionally, the calculated triplet energies for 1,4-azaborinecompounds are much high than the values measured for9,10-diphenylanthracene (Compound Z). Comparing the HOMO, LUMO and T₁ ofthe dibenzo-1,4-azaborine compounds and Ir(ppy)₃, it is believed thatthe dibenzo-1,4-azaborine compounds provided herein can work as a hostfor Ir(ppy)₃ in phosphorescent OLEDs.

It is believed that the dibenzo-1,4-azaborine compounds provided hereinmay be advantageously used over known azaborine compounds for severalreasons. First, without being bound by theory, it is believed thatsubstituents at the 2 and 6 positions of the phenyl attached to theboron atom provide steric protection to the boron atom. In particular,Compound Y, which has an unsubstituted phenyl attached to the boron,shows signs of decomposition during the PL measurement in solutionwhereas Compound 2, which has 2,4,6-triphenylphenyl attached to theboron, do not show signs of decomposition. Secondly, the substituent R₁at the boron may have the least conjugation to the 1,4-azaborine system.This feature may allow an independent electronically and/orphotophysically active group, preferably with 2 or more aryl orheteroaryl groups that are conjugated or fused, to be connected to the1,4-azaborine system for tuning the electronic and/or photophysicalproperties. For example, if a R₁ is 2-quinoline, the 2-quinoline groupcan provide a relatively low LUMO which may facilitate electrontransport and stabilization of negative charge. Some groups may be ableto provide steric protection to the boron atom and electronic and/orphotophysical tuning simultaneously. For example, if R₁ is phenyl andits 2,6 positions are further substituted by aryl or heteroaryl groups,the boron atom is sterically protected, and the 2,6-diphenylphenylmoiety provides a biphenyl conjugation. If R₁ is 1-naphthyl, the boronatom is partially sterically protected and the naphthyl group providesextra conjugation. In addition to further conjugation and stabilizationof charges, the aryl or heteroaryl substituents, preferably with 2 ormore aryl or heteroaryl groups that are conjugated or fused, may providehigh glass transition temperatures and suitable evaporationtemperatures. For example, previously reported Compound X, which has2,4,6-trimethylphenyl attached to the boron, compared to Compound 2, mayprovide low glass transition temperatures and evaporation temperaturestoo low for device fabrication by vacuum processes because the2,6-methyl substituents of Compound X do not provide a high enoughmolecular weight. If higher molecular weight alkyl groups are used, thecompound may melt too easily; and may have poor electronic propertiesfor devices due to too many non-electronically active alkyl groups.Therefore, the dibenzo-1,4-azaborine compounds provided herein areparticularly desirable and may be advantageously used to provide deviceswith improved stability.

In addition, the azaborine compounds provided may be used as fluorescentemitting materials. The dibenzo-1,4,-azaborine compounds provided hereindemonstrate high energy emission, i.e., 400-450 nm, similar to thefluorescence measured for anthracene. For example, the photoluminescencespectra of Compound 2, Compound X and Compound Y are shown in FIGS. 4-6.At 77 K, a low energy emission (>700 nm) is observed in Compound 2 andCompound Y, but not Compound X. The low energy emission may be thephosphorescence of Compound 2 and Compound Y, however, the valuesignificantly deviates from the DFT calculation. While thephosphorescence emission from high energy is expected to be quenched,the phosphorescence of Ir(ppy)₃ type compounds is not quenched byCompound 2 using thin film PL experiments. In devices, the efficiency ofthe device using Compound B as the host with Compound A, an Ir(ppy)₃type compound, as the dopant, is comparable to a standard device usingCSP as the host.

Furthermore, the azaborine compounds provided show an intense deep bluefluorescence (˜410 nm). In particular, a thin film of Compound 2 shows aPLQY of 64%. Therefore, the compounds provided may be desirable for useas fluorescent emitters in OLEDs.

Azaborine compounds are provided, the compounds comprising the formula:

R₁ is a group containing two or more aryl or heteroaryl groups, and thearyl or heteroaryl groups are conjugated or fused. R₃ and R₄ mayrepresent mono, di, tri, tetra, or penta substitutions. R₂, R₃ and R₄are independently selected from hydrogen, alkyl, alkoxy, amino, alkenyl,alkynyl, aryl, and heteroaryl. Preferably, R₂ includes an aryl or aheteroaryl.

In one aspect, the compound comprises the formula:

R′₃, R′₄, R′₅, and R′₆ may represent mono, di, tri, tetra, or pentasubstitutions. R′₁, R′₂, R′₃, R₄, R′₅ and R′₆ are independently selectedfrom hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, aryl, andheteroaryl. At least one of and R₂ is an aryl or heteroaryl and the arylor heteroaryl groups are conjugated or fused.

In one aspect, R′₃, R′₄, R′₅, and R′₆ are independently aryl orheteroaryl.

In another aspect, R′₄ includes aryl or heteroaryl substitutionspositioned ortho to the carbon atom in the aryl or heteroaryl group thatis connected to the nitrogen atom.

Specific examples of azaborine compounds are provided and includecompounds selected from the group consisting of:

In another aspect, examples of azaborine compounds are provided andinclude compounds selected from the group consisting of:

Additionally, a first device comprising an organic light-emitting deviceis provided. The organic light-emitting device comprises an anode, acathode, and an organic layer, disposed between the anode and thecathode, and the organic layer further comprises a compound comprisingthe formula:

R₁ is a group containing two or more aryl or heteroaryl groups, and thearyl or heteroaryl groups are conjugated or fused. R₃ and R₄ mayrepresent mono, di, tri, tetra, or penta substitutions. R₂, R₃ and R₄are independently selected from hydrogen, alkyl, alkoxy, amino, alkenyl,alkynyl, aryl, and heteroaryl. Preferably, R₂ includes an aryl or aheteroaryl.

In one aspect, the compound comprises the formula:

R′₃, R′₄, R′₅, and R′₆ may represent mono, di, tri, tetra, or pentasubstitutions. R′₁, R′₂, R′₃, R′₄, R′₅ and R′₆ are independentlyselected from hydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, aryl,and heteroaryl. At least one of R′₁ and R′₂ is an aryl or heteroaryl,and the aryl or heteroaryl groups are conjugated or fused.

In one aspect, R′₃, R′₄, R′₅, and R′₆ are independently aryl orheteroaryl.

In another aspect, R′₄ includes aryl or heteroaryl substitutionspositioned ortho to the carbon atom in the aryl or heteroaryl group thatis connected to the nitrogen atom.

Specific examples of azaborine compounds that may be used in the devicesare provided, and include compounds selected from the group consistingof:

In another aspect, specific examples of azaborine compounds that may beused in the devices are provided, and include compounds selected fromthe group consisting of:

In one aspect, the organic layer is a blocking layer and the compoundhaving Formula I is a blocking material.

In another aspect, the organic layer is an emissive layer and thecompound comprising Formula I is a host. The organic layer may furthercomprise an emissive dopant. In yet another aspect, the organic layer isan emissive layer and the compound comprising Formula I is a fluorescentemitter.

In one aspect, the first device is a consumer product. In anotheraspect, the first device is an organic light-emitting device.

The materials described herein as useful for a particular layer in anorganic light-emitting device may be used in combination with a widevariety of other materials present in the device. For example, emissivedopants disclosed herein may be used in conjunction with a wide varietyof hosts, transport layers, blocking layers, injection layers,electrodes and other layers that may be present. The materials describedor referred to below are non-limiting examples of materials that may beuseful in combination with the compounds disclosed herein, and one ofskill in the art can readily consult the literature to identify othermaterials that may be useful in combination.

HIL/HTL:

A hole injecting/transporting material to be used in the presentinvention is not particularly limited, and any compound may be used aslong as the compound is typically used as a hole injecting/transportingmaterial. Examples of the material include, but not limit to: aphthalocyanine or porphryin derivative; an aromatic amine derivative; anindolocarbazole derivative; a polymer containing fluorohydrocarbon; apolymer with conductivity dopants; a conducting polymer, such asPEDOT/PSS; a self-assembly monomer derived from compounds such asphosphonic acid and silane derivatives; a metal oxide derivative, suchas MoO_(x); a p-type semiconducting organic compound, such as1,4,5,8,9,12-Hexaazatriphenylenehexacarbonitrile; a metal complex, and across-linkable compounds.

Examples of aromatic amine derivatives used in HIL or HTL include, butnot limit to the following general structures:

Each of Ar¹ to Ar⁹ is selected from the group consisting aromatichydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl,triphenylene, naphthalene, anthracene, phenalene, phenanthrene,fluorene, pyrene, chrysene, perylene, azulene; group consisting aromaticheterocyclic compounds such as dibenzothiophene, dibenzofuran,dibenzoselenophene, furan, thiophene, benzofuran, benzothiophene,benzoselenophene, carbazole, indolocarbazole, pyridylindole,pyrrolodipyridine, pyrazole, imidazole, triazole, oxazole, thiazole,oxadiazole, oxatriazole, dioxazole, thiadiazole, pyridine, pyridazine,pyrimidine, pyrazine, triazine, oxazine, oxathiazine, oxadiazine,indole, benzimidazole, indazole, indoxazine, benzoxazole, benzisoxazole,benzothiazole, quinoline, isoquinoline, cinnoline, quinazoline,quinoxaline, naphthyridine, phthalazine, pteridine, xanthene, acridine,phenazine, phenothiazine, phenoxazine, benzofuropyridine,furodipyridine, benzothienopyridine, thienodipyridine,benzoselenophenopyridine, and selenophenodipyridine; and groupconsisting 2 to 10 cyclic structural units which are groups of the sametype or different types selected from the aromatic hydrocarbon cyclicgroup and the aromatic heterocyclic group and are bonded to each otherdirectly or via at least one of oxygen atom, nitrogen atom, sulfur atom,silicon atom, phosphorus atom, boron atom, chain structural unit and thealiphatic cyclic group. Wherein each Ar is further substituted by asubstituent selected from the group consisting of hydrogen, alkyl,alkoxy, amino, alkenyl, alkynyl, arylalkyl, heteroalkyl, aryl andheteroaryl.

In one aspect, Ar¹ to Ar⁹ is independently selected from the groupconsisting of:

k is an integer from 1 to 20; X¹ to X⁸ is CH or N; Ar¹ has the samegroup defined above.

Examples of metal complexes used in HIL or HTL include, but not limit tothe following general formula:

M is a metal, having an atomic weight greater than 40; (Y¹-Y²) is abidentate ligand, Y1 and Y² are independently selected from C, N, O, P,and S; L is an ancillary ligand; m is an integer value from 1 to themaximum number of ligands that may be attached to the metal; and m+n isthe maximum number of ligands that may be attached to the metal.

In one aspect, (Y¹-Y²) is a 2-phenylpyridine derivative.

In another aspect, (Y¹-Y²) is a carbene ligand.

In another aspect, M is selected from Ir, Pt, Os, and Zn.

In a further aspect, the metal complex has a smallest oxidationpotential in solution vs. Fc⁺/Fc couple less than about 0.6 V.

Host:

The light-emitting layer of the organic EL device of the presentinvention preferably contains at least a metal complex as light-emittingmaterial, and may contain a host material using the metal complex as adopant material. Examples of the host material are not particularlylimited, and any metal complexes or organic compounds may be used aslong as the triplet energy of the host is larger than that of thedopant.

Examples of metal complexes used as host are preferred to have thefollowing general formula:

M is a metal; (Y³-Y⁴) is a bidentate ligand, Y³ and Y⁴ are independentlyselected from C, N, O, P, and S; L is an ancillary ligand; m is aninteger value from 1 to the maximum number of ligands that may beattached to the metal; and m+n is the maximum number of ligands that maybe attached to the metal.

In one aspect, the metal complexes are:

(O—N) is a bidentate ligand, having metal coordinated to atoms O and N.

In another aspect, M is selected from Ir and N.

In a further aspect, (Y³-Y⁴) is a carbene ligand.

Examples of organic compounds used as host are selected from the groupconsisting aromatic hydrocarbon cyclic compounds such as benzene,biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene,phenanthrene, fluorene, pyrene, chrysene, perylene, azulene; groupconsisting aromatic heterocyclic compounds such as dibenzothiophene,dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran,benzothiophene, benzoselenophene, carbazole, indolocarbazole,pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole,oxazole, triazole, oxadiazole, oxatriazole, dioxazole, thiadiazole,pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine,oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine,benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline,cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine,pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine,benzofuropyridine, furodipyridine, benzothienopyridine,thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine;and group consisting 2 to 10 cyclic structural units which are groups ofthe same type or different types selected from the aromatic hydrocarboncyclic group and the aromatic heterocyclic group and are bonded to eachother directly or via at least one of oxygen atom, nitrogen atom, sulfuratom, silicon atom, phosphorus atom, boron atom, chain structural unitand the aliphatic cyclic group. Wherein each group is furthersubstituted by a substituent selected from the group consisting ofhydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, arylalkyl,heteroalkyl, aryl and heteroaryl.

In one aspect, host compound contains at least one of the followinggroups in the molecule:

R¹ to R⁷ is independently selected from the group consisting ofhydrogen, alkyl, alkoxy, amino, alkenyl, alkynyl, arylalkyl,heteroalkyl, aryl and heteroaryl, when it is aryl or heteroaryl, it hasthe similar definition as Ar's mentioned above.

k is an integer from 0 to 20.

X¹ to X⁸ is selected from CH or N.

HBL:

A hole blocking layer (HBL) may be used to reduce the number of holesand/or excitons that leave the emissive layer. The presence of such ablocking layer in a device may result in substantially higherefficiencies as compared to a similar device lacking a blocking layer.Also, a blocking layer may be used to confine emission to a desiredregion of an OLED.

In one aspect, compound used in HBL contains the same molecule used ashost described above.

In another aspect, compound used in HBL contains at least one of thefollowing groups in the molecule:

k is an integer from 0 to 20; L is an ancillary ligand, m is an integerfrom 1 to 3.

ETL:

Electron transport layer (ETL) may include a material capable oftransporting electrons. Electron transport layer may be intrinsic(undoped), or doped. Doping may be used to enhance conductivity.Examples of the ETL material are not particularly limited, and any metalcomplexes or organic compounds may be used as long as they are typicallyused to transport electrons.

In one aspect, compound used in ETL contains at least one of thefollowing groups in the molecule:

R¹ is selected from the group consisting of hydrogen, alkyl, alkoxy,amino, alkenyl, alkynyl, arylalkyl, heteroalkyl, aryl and heteroaryl,when it is aryl or heteroaryl, it has the similar definition as Ar'smentioned above;

Ar¹ to Ar³ has the similar definition as Ar's mentioned above;

k is an integer from 0 to 20;

X¹ to X⁸ is selected from CH or N.

In another aspect, the metal complexes used in ETL contains, but notlimit to the following general formula:

(O—N) or (N—N) is a bidentate ligand, having metal coordinated to atomsO, N or N, N; L is an ancillary ligand; in is an integer value from 1 tothe maximum number of ligands that may be attached to the metal.

EXPERIMENTAL Compound Examples Example 1 Synthesis of Compound 2

2′-bromo-5′-phenyl-1,1′:3′,1′-terphenyl was prepared according to theliterature procedure (Inorg. Chem. 2003, 42, 6824).2′-bromo-5′-phenyl-1,1′:3′,1′-terphenyl (10 g, 26 mmol) was dissolved in10 mL of THF and refluxed with magnesium turnings (0.7 g, 28.5 mmol) for16 h. The reaction mixture was cooled to 10° C., trimethylborate wasadded and the reaction heated to reflux for 16 h. Upon cooling, methanoland ethyl acetate were added and the reaction filtered through a plug ofCelite. Upon removal of the solvent, 9 g (92%) of dimethyl(5′-phenyl-[1,1′:3′,1″-terphenyl]-2′-yl)boronate ester was isolated andused without further purification.

2-Bromo-N-(2-bromophenyl)-N-phenylaniline (1.0 g, 2.5 mmol) wasdissolved in 50 mL of diethyl ether and the solution cooled to −78° C.tent-Butyllithium (10.9 ml, 1.7 molar solution pentane, 18.6 mmol) wasadded dropwise and the reaction mixture allowed to warm to 0° C. Afterstirring for 30 minutes at 0° C., the reaction mixture was thenre-cooled to −78° C. Dimethyl(5′-phenyl-[1,1′:3′,1″-terphenyl]-2′-yl)boronate ester (1.2 g, 3.2 mmol)was dissolved in 10 mL of diethyl ether and added dropwise to reactionmixture. After warming to room temperature, the reaction was refluxedovernight, cooled and filtered through a plug of Celite withdichloromethane. The crude product was chromatographed on silica gelwith 7(3 hexane/dichloromethane and further crystallized fromhexane/dichlormethane to give 1.1 g (79%) of Compound 2.

Example 2 Synthesis of Compound X

Compound X was prepared according to the literature procedure (Org.Lett. 2006, 8, 2241). 2-bromo-N-(2-bromophenyl)-N-methylaniline (0.5 g,1.5 mmol) was dissolved in 50 mL of diethyl ether and the solutioncooled to −78° C. tert-Butyllithium (4.3 mL of 1.7 molar solution inpentane, 7.3 mmol) was added dropwise and the reaction mixture allowedto warm to 0° C. and stirred for 30 minutes. Dimethylmesityldiboronateester (0.37 g, 1.9 mmol) was dissolved in 10 mL of ether and added toreaction mixture dropwise. The reaction mixture was allowed to warm toroom temperature, refluxed for 2 h, cooled, filtered through Celite withdichlormethane and concentrated. The crude product was chromatographedon silica gel with 9/1 hexane/ethyl acetate and further crystallizedfrom hexane to give 0.13 g (55%) of the Compound X.

Example 3 Synthesis of Compound Y

2-Bromo-N-(2-bromophenyl)-N-phenylaniline was prepared according to theliterature procedure (J. Org. Chem. 1961, 2013).2-Bromo-N-(2-bromophenyl)-N-phenylaniline (1.5 g, 3.7 mmol) wasdissolved in 50 mL of diethyl ether and the solution cooled to −78° C.tert-Butyllithium (10.9 mL, 1.7 molar solution in pentane, 18.6 mmol)was added dropwise and the reaction mixture allowed to warm to 0° C.After stirring for 30 minutes at 0° C., the reaction mixture was thenre-cooled to −78° C. Dichlorophenylborane (0.63 ml, 4.8 mmol) wasdissolved in 10 mL of diethyl ether and added dropwise to reactionmixture. After warming to room temperature, the reaction was refluxedovernight, cooled and filtered through a plug of Celite withdichloromethane. The crude product was chromatographed on silica gelwith 8/2 hexane/ethyl acetate and further crystallized from hexane togive 0.56 g (45%) of the Compound Y.

Example 4 Synthesis of Compound 49

To bis(2-bromophenyl)amine (10.0 g, 30.6 mmol), 1-fluoro-4-nitrobenzene(5.6 g, 39.8 mmol), and potassium carbonate (5.49 g, 39.8 mmol) wasadded 20 mL of DMSO. The reaction mixture was heated in an oil bath 145°C. for 48 h. After cooling to room temperature, 100 mL of water wasadded and extracted with 3×50 mL CH₂Cl₂. The combined extracts werewashed with 2×50 ml water, dried over sodium sulfate and evaporated togive a dark brown solid. The crude product was chromatographed on silicagel eluted with 75:25 hexane/CH₂Cl₂ followed by 50:50 hexane/CH₂Cl₂ togive 5.0 g of product as a yellow solid. NMR and GC/MS confirmedproduct.

2-Bromo-N-(2-bromophenyl)-N-(4-nitrophenyl)aniline (4.8 g, 10.71 mmol)and tin(II)chloride dihydrate (10.2 g, 53.6 mmol) were dissolved inethanol (50 mL) and tetrahydrofuran (50 mL) and he solution heated toreflux. After 3 h, an additional 2.0 g tin(11) chloride was added andthe reaction mixture heated for an additional 2 h at reflux. Aftercooling, the reaction was poured into 100 ml of ice and 50% aqueoussodium hydroxide solution was added until pH 14 was reached. Theresulting caustic solution was extracted 3×75 mL with CH₂Cl₂. Thecombined organics were washed with 75 mL of water, dried over sodiumsulfate and evaporated to give an orange solid. The crude product waschromatographed on silica gel eluted with 50:50 hexane/CH₂Cl₂ to give3.8 g of product as a yellow solid. NMR confirmed product.

In a flask, N,N-bis(2-bromophenyl)benzene-1,4-diamine (0.5 g, 1.2 mmol),iodobenzene (2.44 g, 11.96 mmol), potassium carbonate (0.628 g, 4.54mmol) and copper powder (0.038 g, 0.60 mmol) were combined and heated inan oil bath at 200° C. for 20 h. After cooling to room temperature, 25ml of water was added and extracted with 3×15 mL CH₂Cl₂. The combinedextracts were washed with 2×20 mL water, dried over sodium sulfate andevaporated leaving a dark brown liquid. The crude product waschromatographed on silica gel eluted with 90:10 hexane/CH₂Cl₂ followedby 75:25 hexane/CH₂Cl₂ to give 0.35 g of product as a white solid. NMRand GC/MS confirmed product.

To a solution ofN,N-bis(2-bromophenyl)-N′,N′-diphenylbenzene-1,4-diamine (1.5 g, 2.5mmol) in ether (50 ml) at −78° C. was added tert-butyllithium (7.5 mL,1.7 M in pentane, 12.7 mmol) dropwise. The reaction was warmed to 0° C.for 30 minutes before being recooled to −78° C. A solution ofdimethyl(5′-phenyl-[1,1′,3′,1″-terphenyl]-4′-yl)boronate (1.3 g, 3.4mmol) in 25 ml of ether was added dropwise, the bath was removed and thereaction mixture allowed to warm to room temperature, after which it washeated at reflux overnight. After cooling to room temperature, hexaneand EtOAc were added and the mixture filtered through celite and thefiltrate was evaporated to give a yellow solid. The crude product waschromatographed on silica gel eluted with 98:2 hexane/CH₂Cl₂ to give 0.5g of Compound 49. NMR and MS confirmed product.

Example 5 Synthesis of Compound 53

4,4,5,5-Tetramethyl-2-(2-phenylnaphthalen-1-yl) [1,3,2]-dioxaborolanewas prepared according to the procedure of Spivey et al., J. Org. Chem.2003, 68, 7379. To a solution ofN,N-bis(2-bromophenyl)-N4,N4-diphenylbenzene-1,4-diamine (0.5 g, 0.88mmol) in 25 ml ether, cooled in a dry ice/acetone bath to −78° C., wasadded tert-butyllithium (2.6 mL, 4.4 mmol, 1.7 M in pentane) dropwise.The ice bath was removed and the reaction mixture was allowed to warm to0° C. and stirred for 30 min. The reaction mixture was recooled to −78°C. and a solution of4,4,5,5-tetramethyl-2-(2-phenylnaphthalen-1-yl)[1,3,2]-dioxaborolane(0.38 g, 1.14 mmol) in 10 mL of ether was added dropwise. After stirringfor 30 min. at −78° C., the bath was removed and the solution allowed towarm to room temperature and subsequently heated to reflux overnight.After cooling, the reaction was quenched by adding 2 ml MeOH andfiltered through celite, washing with CH₂Cl₂. After evaporation of thesolid, the crude product was chromatographed on silica with 90:10hexane:CH₂Cl₂ followed by 75:25 hexane:CH₂Cl₂ to give 0.15 g of Compound53. NMR and LC/MS confirmed product.

Device Examples

All device examples were fabricated by high vacuum (<10⁻⁷ Torr) thermalevaporation. The anode electrode is indium tin oxide (ITO). The cathodeconsisted of 10 Å of LiF followed by 1,000 Å of Al. All devices wereencapsulated with a glass lid sealed with an epoxy resin in a nitrogenglove box (<1 ppm of H₂O and O₂), and a moisture getter was incorporatedinside the package.

The organic stack of the Device Example 1 in Table 2 consists ofsequentially, from the ITO surface, 100 Å of E1 as the hole injectionlayer (HIL), 300 Å of NPD as the hole transporting layer (HTL), 300 Å ofCompound 2 doped with 15 wt % of Compound A as the emissive layer (EML),50 Å of Compound 2 as the ETL2 and 400 Å of BA1q as the ETL1. Compound 2evaporated at ˜230° C. at ˜10⁻⁸ Torr.

Comparative Device Example 1 is similar to the Device Example 1 exceptthe EML is Compound B doped with 10 wt % of E1 and the ETL2 is CompoundC.

As used herein, the following compound have the following structures:

Particular materials for use in an OLED are provided. In particular, thematerials may be used as host materials and/or emitting dopant in theemissive layer of such a device. The materials may also be used innon-emissive layers, such as the blocking layer. The compounds providedherein may improve device lifetime.

TABLE 2 At 1000 cd/m² Device 1931 CIE LE EQE PE Example Host % E1 ETL2 xy V [V] [cd/A] [%] [lm/W] 1 Compound 15 Compound 0.3202 0.6263 5.7 32.99.2 18.0 2 2 Comparative CBP 10 BAlq 0.346  0.614  7.0 33.4 9.2 15.0 1

From Table 2, it can be seen that the efficiency of the device usingCompound B as the host with Compound A, an Ir(ppy)₃-type compound, asthe dopant, is comparable to a standard device using CBP as the host.

It is understood that the various embodiments described herein are byway of example only, and are not intended to limit the scope of theinvention. For example, many of the materials and structures describedherein may be substituted with other materials and structures withoutdeviating from the spirit of the invention. The present invention asclaimed may therefore includes variations from the particular examplesand preferred embodiments described herein, as will be apparent to oneof skill in the art. It is understood that various theories as to whythe invention works are not intended to be limiting.

The invention claimed is:
 1. A compound comprising the formula:

wherein R′₄, may represent mono, di, tri, or tetra substitutions;wherein R′₅ and R′₆, may represent mono, di, tri, tetra, substitution;wherein R′₃, may represent mono, di, or tri substitutions; wherein R′₁and R′₂, are independently selected from aryl and heteroaryl, whereinR′₃, R′₄, R′₅, and R′₆ are independently selected from hydrogen, alkyl,alkoxy, amino, alkenyl, alkynyl, aryl, and heteroaryl; and wherein thearyl or heteroaryl groups are conjugated or fused.
 2. The compound ofclaim 1, wherein R′₃, R′₄, R′₅, and R′₆ are independently aryl orheteroaryl.
 3. The compound of claim 1, wherein R′₄ includes aryl orheteroaryl substitutions positioned ortho to the carbon atom in thephenyl group that is connected to the nitrogen atom.
 4. A compoundselected from the group consisting of:


5. The compound of claim 1, wherein the compound is selected from thegroup consisting of:


6. A first device comprising an organic light-emitting device, furthercomprising: an anode; a cathode; and an organic layer, disposed betweenthe anode and the cathode, wherein the organic layer further comprises acompound comprising the formula:

wherein R′₄, may represent mono, di, tri, or tetra substitutions;wherein R′₅ and R′₆, may represent mono, di, tri, tetra, substitution;wherein R′₃, may represent mono, di, or tri substitutions; wherein R′₁and R′₂, are independently selected from aryl and heteroaryl, whereinR′₃, R′₄, R′₅, and R′₆ are independently selected from hydrogen, alkyl,alkoxy, amino, alkenyl, alkynyl, aryl, and heteroaryl; and wherein thearyl or heteroaryl groups are conjugated or fused.
 7. The first deviceof claim 6, wherein R′₃, R′₄, R′₅ and R′₆ are independently aryl orheteroaryl.
 8. The first compound of claim 7, wherein R′₄ includes arylor heteroaryl substitutions positioned ortho to the carbon atom in thephenyl group that is connected to the nitrogen atom.
 9. The first deviceof claim 6, wherein the compound is selected from the group consistingof:


10. The device of claim 6, wherein the compound is selected from thegroup consisting of:


11. The device of claim 6, wherein the organic layer is a blocking layerand the compound having Formula II is a blocking material.
 12. The firstdevice of claim 6, wherein the organic layer is an emissive layer andthe compound comprising Formula II is a host.
 13. The first device ofclaim 12, wherein the organic layer further comprises an emissivedopant.
 14. The first device of claim 6, wherein the organic layer is anemissive layer and the compound comprising Formula II is a fluorescentemitter.
 15. The first device of claim 6, wherein the device is aconsumer product.
 16. The first device of claim 6, wherein the device isan organic light-emitting device.
 17. A compound selected from the groupconsisting of:


18. A first device comprising an organic light-emitting device, theorganic light emitting device comprising: an anode; a cathode; and anorganic layer, disposed between the anode and the cathode, wherein theorganic layer further comprises at least one compound selected from thegroup consisting of: